Protective device.



R. G. SANDS.

PROTECTIVE DEVICE.

APPLICATION FILED MAR. I9. 1917.

Patented Aug. 27, l9l 8.-

JAM

With-w i1 I TED STATES ()FFIQE.

ROY GRANVILLE SANDS, OF WAUKEGAN, ILLINOIS, ASSIGNOB, TO FRANK B. COOK COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

PROTECTIVE DEVICE.

Specification of Letters Patent.

Patented A11 27, 1918.

Application filed March 19, 1917. Serial No. 155,832.

To all whom it may concern Be it known that I, ROY GRANVILLE SANDS, a citizen of the United States, residing at aukegan, in the county of Lake and State. of Illinois, have invented new and useful Improvements in Protective Devices, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawing, forming a part of this specification.

My invention relates to protective devices and more particularly to lightning arresters such as are used principally for outdoor service in connection with telephone lines, an object being to provide an improved and simplified device of this character which is cheap to manufacture, easy to install, and positive in its operation. A feature of my invention is an improved form of discharge clip preferably made of sheet metal and formed so as to take the place of the solid copper and carbon blocks previously em ployed. Vhile there are certain advantages in the use of carbon blocks, there are other disadvantages when compared with metal blocks. For instance, in the use of carbon discharge blocks, due to the arcing through the insulating separator between the blocks, the carbon disintegrates, the dust settling between the blocks and causing a short circuit. This was obviated by the use of solid copper blocks, which have displaced the carbon blocks to some extent, but on account of the high cost of the copper blocks their use has been prohibitive in many places. My improved discharge clip, which is adapted to take the place of the solid blocks, is formed out of sheet metal, preferably copper, and of a suitable shape to be inserted and held between the terminal clips of the arrester. Other features of my invention will be more particularly pointed out in the ensuing specification and claims.

For a better understanding of my invention, reference is to be had to the accompanying drawings, in which like reference characters indicate like parts and in which Figure 1 is a plan view of the preferred form of my invention;

Fig. 2 is a side elevation of the same;

Fig. 3 is a sectional view along the line 33 of Fig. 1;

Fig. 4 is a sectional view along the line 4- of Fig. 1;

Fig. 5 is a perspective view of the pre ferred form of discharge clip;

Fig. 6 shows the preferred form of insulating strip, which is inserted between the pairs of discharge clips and Fig. .7 shows in detail a portion of the common mounting strip with its spring fingers.

Referring now more particularly to the preferred form ofmy invention as illustrated in the drawings, it comprises a circular base A preferably of procelain and having a central rib 1 on its upper face, to which is attached an elongated U-shaped mounting strip 2 by means of screws 3 which eXtend througlrthe mounting strip 2, the

I base A and a mounting bracket 4. A sleeve 5 is interposed between the rib 1' and the strip 2 (shown more particularly in Figs. 3 and 4-) so as to keep the bottom edges of the U-shaped mounting strip 2 clear of the base. Aplura-lity of spring fingers 2 are formed along the sides of the mounting strip 2, thes fingers being adapted to receive and hold the discharge clips in a manner as will be hereinafter described. This mounting strip 2 also acts a common terminal for the individual arresters. A plurality of individual spring terminal clips 6 are also provided, being mounted opposite the spring fingers 2. Each terminal clip 6 is mounted I by means of a screw 7 and nuts which act as a terminal connector for the particular clip.

The arrester is adapted to receive the standard carbon or copper blocks, or my inr proved discharge clip, shown more particularly in Fig. 5. I have illustrated both forms of the discharge element in the drawings, the solid blocksbeing shown in all but the two left-hand terminals of Figs. 1 and 2,

As shown in Fig. 5, my improved discharge clip 10 preferably comprises a U- shaped element having legs 8, 9, the leg 9 being preferably bent inwardly at its end 9 so as to limit the compression of the free end of the clip. The :leg 8 has its edges 8, 8 bent outwardly so as to act as a guide and embrace the spring fingers 2 or terminal clips 6 when the clips are pushed into place. These guiding edges also act to prevent a lateral displacement of the clip after it has been seated.

An insulating element 11 (shown more particularly in Fig. 6) preferably composed of mica or celluloid, is placed between each pair of discharge Clips as is shown in the drawings. Thus each pair of discharge clips is insulatingly separated, the distance of separation depending, of course, upon the use to which the device is put.

Fig. 4, which is a cross-section through the solid blocks 13, shows how the solid blocks may be used.-

In the use of the device, the individual terminals 7 are connected to the various telephone lines which are to be protected, and the terminal 12, which is connected to the common mounting strip 2, is connected to ground.

Should any of the discharge clips be rendered useless due to a discharge of lightning or a. high-tension current, they may be read.- ily replaced by simply withdrawing them upwardly and out of engagement with the spring clips6, 2. Ordinarily a cleaning of the adjacent faces of the legs 9 will render them fit for further use. If necessary, a new insulating strip 11 may be put in place. To insert the clips, they are simply placed with the legs 9 together and an insulating strip 11 between them and then pushed downwardly between a pair of. spring fingers 6, 2 until the clips are seated on the rib 1.

This keeps the clips clear of the face of the base so that any accumulated dust or foreign matter will not shortseircuit them.

A thin metal cover may be placed over the protector if desired, this being indicated by the dotted line 13 in Fig. 2. A spring 14 is provided to hold the cover in place, being adapted to press against the inner surface of the side of the .cover as will be readily understood from an inspection of the drawings- For the purpose of illustrating my invention I have chosen a preferred form but it Copies of this patent may be obtained for will be apparent that changes and modifications will readily occur to those skilled in the art and therefore I do not desire to be limited to the exact structure shown and described but aim to cover all that Which comes within the spirit and scope of the appended claims.

\Vhat I claim as new and desire to secure by Letters Patent is 1. An arrester comprising a base of dielectric material having an elongated centrally disposed rib on an upper face of the base, an elongated inverted U-shaped mounting strip secured to said rib, a plurality of spring fingers mounted on said face of the base adjacent the mounting strip, a plurality of corresponding spring fingers on the mounting strip anda pair of discharge elements removably held by each pair of lingers in contact therewith.

2. A lightning arrestercomprising a pair of parallel finger terminals, a pair of yieldable U-shaped sheet metal discharge clips each having one leg engaging one of said fingers, guiding means for preventing lateral displacement of the clips, and an insulating element slightly separating the other legs of the clips.

A discharge clip for lightning arresters con'iprising a yieldable U-shaped element formed from sheet metal and having guiding means disposed along one leg adapted to engage a spring finger holding terminal.

4. A. discharge clip for lightning arresters comprising a yieldable U-shaped element formed from sheet metal and having guiding means disposed along the side edges of one leg.

In witness whereof, I have hereunto subscribed my name.

R.OY GRANVILLE SANDS.

five cents each, by addressing the Commissioner of Patents. Washington, D. ,G. 

